Inquest launched after police use stun gun on unarmed man at Vancouver airport.

"I've asked for a review relating to the use of Tasers. ... This is a tragic and grievous incident. We want to find out answers that can prevent these things from happening in the future," Stockwell Day, the public security minister, told the Canadian parliament.

Many Canadians were shocked by the images of Dziekanski writhing on the floor moments before he died.

Some people complained to radio and TV shows that police acted too quickly to stun a man who did not appear to be threatening them.

Dale Carr, a spokesman for the RCMP, urged the public to withhold their judgment of what they see on the video until the police can explain their conduct while testifying under oath at a coroner's inquest.

He said an investigation by a homicide team will take another 30 to 45 days.

"The inquest will be the venue in which the contents of the video and the actions of police will be scrutinised," he said in a statement.

Penny Priddy, a politician from the opposition New Democratic Party said, "The screams of a dying man echo throughout the country" and that Canadians wanted answers before more lives were lost.

"Is it standard operating procedure for the RCMP to use Tasers when there is no obvious physical threat?" she asked Day in parliament.

'Unsuitable reaction'

Piotr Ogrodzinski, Poland's ambassador to Canada, said the video had deeply upset him and said Warsaw wanted to learn all it could about an investigation into the case.

"The reaction of the RCMP officers was unsuitable to the situation. What I've seen was that Mr. Dziekanski [was] a person who was agitated, frustrated, I think terrified, but not aggressive. He was not making a gesture that he intended to fight anybody," Ogrodzinski told Reuters.

"He didn't know what to to do. In fact, he was in search [of] help. That is why it is a really very sad and deeply moving film to watch."

Dziekanski flew to Canada to live with his mother in the western Canadian city of Kamloops in British Columbia. She had told him to wait for her at the baggage area.

But this meant he never passed through the customs section to enter the main part of Vancouver's airport, where she was waiting.